Building construction



April 30, 1940.

A. J. EDGE ET AL BUILDING CONSTRUCTION Filed Jan. 27, 1937 ALLA;

Y@ N51 s? ws '//Sf we f 5o F195 Fig. 7

Fig/.1A E Figi/1 H9321 FigfLA 4 Sheets-Sheet 1 A. J. EDGE ET AL2,199,152 BUILDING coNs'rRUcTIoN Filed Jan. 27. 1937 April 3o, 1940.

, v 4 Sheets-Sheet 2 fig 11 PYT/0 FigJz l [L Il Il I L Il L53 ILS! A. J.EDGE El AL BUILDING CONSTRUCTION April 30,1940.

4 'Sheets-Sheet 3 Filed Jan. 27. 1937 Fig. E 2

' H929 f'gos H93/ Figz INVENTO 6 'f' @47s Fig. s@ Hwy H940 Ffyffl.Apl30;1940. A.J.EDGE ErAL BUILDING' CONSTRUCTION Filed Jan..27, i937 4sheets-sheet 4 R T N Patented rApr. 30, 1940 umts-D! STATES BUILDINGCONSTRUCTION y `Alfred J. Edge, Savannah, Ga., and Walter S.

Edge, Pittsburghl?a."

n Application January 27, 1987, Serial'No.' 122,638

1 Claim.

Our invention relates to the framing for structures suclr as posts,poles, bridges, buildings of various kinds, but its greatest kusa-wethink, lies in smallf low cost dwellings. Apparently, it may beleconomically used' as a substitute for Wooden timber for manylpurposes. v

One object of our invention is to produce structural members of veryhigh eiciency.

Another object is to produce structural framingy membersof very lightweight.

Another object is toproduce a framed structure' with self containedconnections provided for interior' or exterior coverings or both,greatly facilitating its-rapid erection.

Another' object is to produce structural members which` lend themselvesto very easy erection andi veryA simple and strong field connections.

Another object is tov produce a structural frame which providesthe'maximum facility for the run- 0, ingsof electric ducts', pipes, etc.,inwalls or oors.

Another objectl is to produce structural members which, when combinedwith cement stucco, plaster or a concrete floor, will5 act rwith thesame to-.carry stressV as combination members, thereby, greatlyincreasing: the eiciency of' construction. This is;not' truel of manyforms ofy combined steel andi cement construction now in common use.Wefare aware that many attempts havebeen madev and are beingmade toproducethe, so called; low vcostfst'eelhouse and we are familiar witlrmany: of' these designs, but,1so far asy we know no one. has succeededin producing a satisfactory steel house at av cost equal to or lowerthanv a. similar house could be built out of wood inr the' samelocality'.l

' By A the use .of the designs andmethods of manufacture herein.disclosed,`coupled` with the special combination of materials which weemploy, WeY are able to producefreprooff construction at ai costconsiderably below the cost of standard wondv construction. Ourmaterials weigh less and require. less labor for their erection. As atypical example, we are producing metal beams as a-.substitute forwooden beams, having equal strength, Weighing one n fth and costingy onehalf as, much. as wood. In the. design of` structural steel beams andwelded joists (electrically welded assemblies` of steelzparts) unittension and compression stressesof 16,000to2- 18,000 pounds per squareinch are commonly employed. This is due to the fact that the elastic,limit of the steel ofwhich theS7 are made may be as. lowas 32,000 poundsper squareinch and ahigher. workingV stresswould recl'ucetheA factor ofsafety too much. With such l'owworking stresses, steel cannot competewith wood inl cost except possibly in longer spans.

In our studiesto develop a lower cost material for housing: andLother-structures, we were led to consider thesuperior properties of colddrawn wireand cold: rolled." steel. alow carbon steel wire having anultimate tensile strength off115,0'00 pounds per'square inch' with anVelasticli-mitveryvclose to the ultimate. By increasing the carbon and"vmanganese, we have produced wire whose ultimate strength is close1:0408-,000'pounds per square'inch and a strength of 2205000 pounds perVsquare1 inch is being obe tained commercially as an every day matter.

High; carbon hot rolled steel can be. produced, having a hightensile'strength. It is frequently lacking in uniformity, is apt tobegbrittleand is not suv reliable ashot rolled structurall gradeA steel and'isydilficult" to work. Wire, however, by its very natureandprocess ofmanufacture, is much more uniform-1 and reliable'.

In order `to take advantage of the superior properties of' wire, it mustbe assembled into structural units and-thiswe have done inl a number' ofways, as thisA application will disclose. Resistance welding, similartoV that now in common use, was employed, but We found that it It iseasy to produce f would not givethe resul-ts necessaryto'insure success.taken tdi-ind alcure for this-trouble. Weiinally succeeded perfectingamethod and: an apparatusL which` g-ave usy the desired results and thisforms the basis for' anotherapplication forl a patent, Seriali No.41223880, filed January 28, 1937.

Another weakness of assemblies made by ordinary weldingwas theYeccentrlcity of all' connections, which producedhighv secondary stressesinvmembersvof the unitl which, of course, greatly reduceclA itsefficiency. 'Iliis weakness hasalso been! overcome byV our .weldingprocess.

`We have alsotaknadvantageof the different qual-itiesA possessedbydifferent kinds off steel wire', which was firstA disclosed inapplication 94,985: by Walter S; Edge, filed-August 8, 1936 (new PatentV2,103,897). v Our'basicz idea in the production of low cost structural.members ofi high: eiciency isl to first, weld or otherwise assemble,them into fiat sheets which may` be; woundt into coils.Y for'convenience in. liia-ndli-ng,v Standard' Weldingmachines of the ty-penow in use will notv perform this function satisfactorily. The method ofWelding must be changed and, for the most efficient typefof structuralmembers, certainof the longitudinal wires, which would.. normally remainparallel to` the rest,

A long series ofexperiments were underare moved back and forward toproduce certain patterns which are required.

The pattern of the mesh, which will be normally assembled on themachine, will be a multiple of the fabric required for any specicmember. As it passes through the machine, the stay or connecting wiresbetween adjacent members, will be cut so that the result will be anumber of strips or rolls, each one being equivalent to a structuralmember, but, of course, in an uninished form. These individual strips orrolls will then be cold formed into the nal shape required, either bycold pressing or cold rolling, and be cut into convenient lengths.Paintingor galvanizing or other suitable methods may be employed as aprotection against corrosion.

In said Patent 2,103,897 a product known as a plaster ground or plasterbase was described. The structural members herein described are designedto work with this product and others similar to it. The projecting endsof wires shown on many of the structural members in this presentapplication are provided as a support and anchorage for the plasterbase, etc.

VWhen the structural members are erected in their final position, theplaster base sheet is simply pressed against the protruding ends of thewires, forcing them through the backing sheets and the projections arethen bent over to engage the wires of the plaster base and thus firmlylock the Whole together Without the need of any other fastening means.The subsequent coating of plaster, stucco or concrete, as the case maybe, produces a completely bonded structure. When the structural members,herein described, are used in floor construction, in combination With aconcrete door slab, the projecting vertical wires at the top of the beamextend up into the concrete floor slab and thoroughly bond the steelbeam to the concrete, thereby producing a Very eilcient yT beam ofcomparatively small dead weight. Where a plastered ceiling is used onthe underside of the beam, the plaster base is locked on by bending theends of the vertical wires which project from the underside of the beam.When the ceiling has been plastered, the lower sides of the steel beamsare thoroughly braced against buckling and their eciency is muchincreased.

In the accompanying drawings, Figure 1A is a plan View of a typicalcommercial resistance weld as made with soft wire and Figure 2A is aside View of the same weld. In Figure 3A is shown a plan View of a weldmade by bringing together a hard drawn wire and a soft wire and weldingthem by our process and Figure 4A is a side view of the same weld.Figure l is a plan View of one of the simplest forms of structuralmembers and Figure 2 is an end elevation of it. Figure 3 is a side Viewof the structure shown in Figure 1 after it has been pressed or formedinto its iinal shape and in Figure 4 is shown an end View of Figure 3.Figure 5 is a plan view of another form of structural member and Figure6 is an end elevation of it. Figure 7 is a side View oi the structureshown in Figure 5 after it has been pressed into its nal shape andFigure 8 is an end View of Figure 7. Figure 9 is a bottom plan view ofthe structure shown in Figure 7. Figure 10 is still another form ofstructural member and Figure 11 is an end view of it. Figure Y12 is aside view of the structure shown in Figure l0 after it has been pressedinto its nal form and Figure 13 is an end View of Figure 12. Figure 14is still another form of structural member which is shown in an endelevation in Figure 15. In Figure 16 is shown a side view of thestructure shown in Figure 14 after it has been formed into its nal shapeand Figure 17 shows an end View of Figure 16. In Fig-ure 18 is shown aside view of a structural beam of a U shaped cross section. In Figure 19is shown an end elevation of it. Figure 20 is a section on line I--I andFigure 21 is a bottom plan of the structure shown in Figure 18. InFigure 22 is shown still another type of a structural member. In Figure23 is shown a partial side View after it has been formed into its nalshape. Figure 24 shows a partial plan view of the bottom of thestructure shown in Figure 23 and Figure 25 is an end View of thestructure shown in Figure 23. Figure 26 shows another type of structuralmember and Figure 27, still another, both of which are adapted to beformed into members having a U or V or a box cross section. In Figure 28is shown a side view of a beam or column section and Figures 29 and 30show typical cross sections of such a beam or column. Figure 31 shows across section of a beam having a V cross section and Figure 32 is asection showing another modication of this idea.

In Figure 33 is shown a cross section of a structural beam in which theprojecting members at top and bottom are bent into loops or eyes toserve as an anchorage for other structural material. Figures 34 and 35show other modifications of the same idea. In Figure 36 is shown astructural member adapted to be formed into a partition stud and Figure37 shows a cross section of the structure shown in 36 after forming intoits iinal shape. In Figure 38 is shown a side View of a structural beamof still a diierent pattern. Figure 39 shows an end view of Figure 38.In Figures 40 and 41 are shown sections of other forms of structuralmembers which can be readily formed from Welded structures in a similarmanner. In Figure 42 is shown a plan of a structural fabric in whichtrussed beams of a V cross section are incorporated to stifen thestructure (see application 94,985 by Walter S. Edge, led, August 8,1936) which gives a structure suitable for a base for iioor constructionor a plaster base. Figure 43 is an end view of Figure 42 and Figure 44is a side View of Figure 42.

In Figure 45 is shown a sectional View of a portion of a buildingshowing how the structural membersshown in previous gures, are used andcombined to form a complete structure and how the plaster base and oorbase described in other applications by Walter S. Edge, are combinedwith the structural beams to iinish the structure. In Figure 46 is showna sectional View on line II-II in which other details are made clear.

Referring now to the figures in detail, it Will be seen that Figure lconsists of a fabric or grille made up of parallel spaced members, 41,intersected by and rigidly connected to transverse spaced members 48 and49. Members 41 are preferably of high strength material such as highelastic limit steel, for example, hard drawn Wire or cold rolled steel,and may be any cross section, round, at or deformed. Members 48 areshown to be continuous from side to side but members 49 are cut atcertain points. When the structure, shown in Figure 1 is formed into theU cross section shown in Figures 3 and 4, the cuts in members 49 allowportions of these members to protrude below the bottom of the structuralbeam. These projections from the top and bottom of the beam serve toprovide a very exarsenite cellent means for; attaching other structuralma,- terial such as plaster base; etc.,to` the-structural framework;Members 4'8 and 49 are-preferably made of a ductile material such as..soft steel;`

NotA only willlthis; material withstandE the stresses dueto coldf'forming to, shape better, but a better weld results from thecombination. of a hard drawn `steel with: a soft` steel. i Theconnections between members 4T, 48J and 49` areA described asf` rigid;Ordinary commercial: welding will not produceA this. result with thesteels: which- `we prefer to use.. Not; only should the weldsy be strongenough .to developfthev full strength! of themembersg. but there shouldber as littler eccentri'city: as. possibleV at. the. connections. By themethod of; welding: which we have. developed, the connections willdevelop. the full strength ofv a high. tensile. wire,. not onlyy at'vthe. Weldbut for alength including. anumber of: weldsi andeccenapplication by'us,v Serial No. 122,880, flledJanuary 23,1937., f y

- As set forth,y in said-a application, wiresy or' rods are: assembled?superposed relationy asshown ,in Figs.. 1A and ZAfor.example;Whereuponwelding heat' andpressure are applied, the heat and thepressure being continued: until the tWo members occupy a common planeasshown in Figs. 3a and 4a, for example.` f

A structural beam such asV the one shown in Figures 3' and 4, will showa surprising amount of strengthY and; stiffnessbut of course, is4 notAas eicient, as one inL which diagonal bracing is introduced: By usingWelds ofthe type shown in Figures 3A and 4A, theresisting., moment atthe welded joints is doubled and; by still further flattening, the Weld.at the instant of welding, While the. metalI is still hot, the strength;of the joint is still 4further increased' in the plane ofthe fabricWithout. weakening the structural. members between the joints-inA anyrespect. ByI this means; the rigid' frame type of structural' member canbe made quite eicient.

In Figure 5 We show a plan View of a structurall member in which oneform of. diagonal or web: bracing is introduced. In ligures 5,. 6,y '7,8

and 9, longitudinal members 50 are straight, spaced' and:- parallel andare preferably of high tensile materialsuch ashardI drawn Wire or coldrolled steel. Intersecting them at regular intervals are transversemembers 5| and 52 respectively. When th'e structureshown in Figures 5andA 6 is' folded' aroundV the two interior members 50., a. section yof- UA form. is produced (see Figure 8), which is quitek Well braced intwoplanes lat right angles to` each other. This. design is! really acompromise between. a.v real truss and a rigid framebut our tests giveit quite a good rati-ng for efficiency.. Obviously, here-, strength ofconnectionsrv and freedom fromeccentricity arel im# portant. In, this:design members 5I andl 52 should preferably *bev of. a. comparativelysoft material such as soft' wire.

In. Figure 10.I is shown still. another type of structure in which 53and 54are parallelspaced members, preferably madeof hard drawn WireWhile membersI 55 are parallel' and: spaced: and. intersect 53 and 54 atan oblique angle andiare rigidly` connected at theiry intersections.When this structure is folded about member 54, a unit having a V-sl'iapedfcrossl section results and if 4 the foldingv is completed,-thesection shown in are bonded into a. concretel floor slab, the-unitvWilli develop high efficiency: On the: other hand, members 53 mayberigidly connected at two: or`

more points and an: efficient. Warren truss; is ob.-

tained.. o

In Figures 14', 15,16, and 17 is shownfa type of structural member, Welladapted; to serve asi a partition or exterior: wall stud. Here,longitud-: nal members* Sli/'are preferably of. a strong and stiffmateriall such`v ashard drawn wire. and diag;-

onal bracing members 51 may be of, the same.

material; 'Iransversemembers, 5l!r should. beof a relatively softermaterial. They may eitherextend beyond the outside of the members 56; atalternate endsv as shown at 59- or they `may extend at both'. ends. orthey maybe cut. flush with the edge, if desired- Again the projectingends may be bent. intor loops or' eyes (see Figures 33, 34 and 35)'. to;better servev as an anchorage for other structural. material such as aplaster base or iioor base. Figuresl and 1'7y show the-completed form ofthisl stud and it` isat once appare ent, as our tests have showrr,y thatit is very eilicient,v acting as a. beam` inthe plane of its greatestvdimension. Here, again'` the eflciency of, the connections is` veryvimportant.

In: Figures 18,191, and 21 a-re `shown views of a ni'shed structuralbeam whichv may be formed from a. flat fabric by cold pressingjorcoldrolling; 'Ifhe top may be open as` shown in Fig;-

'wallsg the other structural. materialy closes .the

openside of thefll but When used. as; a column,

the'. box section may be necessary, In Figures 22,213, and 24 and 25 isshown a design in which this feature is covered. In Figure 22 is shownafl'at sheet of" welded fabric which the ,lnished structural4 beam is tobe formed from. rIfhis-r fab.- ric, canl be made-on welding machines,now in Gommoni use, with certain mechanical.- changes and with acomplete change in the welding mechanism. The machinecan either turnYout asingle continuous cold rolling or forming process, cutting them'yto length either before or after forming. The stresses setk up4 by thisprocess, inthe fabric-.structure are considerable but the` softermetalusedinthe connecting members 64 of Fig,-

ures 22, etc., can easily withstand this kindA of treatment.

In'Figure 26 isn shown still anotherV type of f ystructural member inwhich longitudinal mem`v bers 61 are preferably of stiff material anddil-4 agonalmembers'are of softer material. Memf bers 68 are rigidly.connected; to members G1 and this' may be done by bringing one above theother, as shown, and Welding them or onei may 'be brought against theside `of the otherand welded as shown in Figure 27. While. thesepatterns are the onlyA ones shown, alnumber of.v other combinations andYarrangementsv arey evidently possible and we do not Wish tobe. limited:onlyV to these designs. Y.

AIn Figure 28 We show a side elevation of a beam or column which isshown in section in Figure'29` and an alternate design in; Figure 30.

vI-Iere longitudinal'. members lil and. 13 are pref.-

erably of a stiff material such as hard drawn Wire While cross members12 are of softer material. The structure here shown isfa closed or boxsection, is thoroughly braced and showed under test a very highefliciency. In Figure 29 is shown the cross section resulting fromfolding a flat structure such as was shown in Figures 26 and 27. Asimpler and better column section is formed by omitting onelongitudinal, 14, Figure 30, and tying or welding members 15 to member-14 as shown at 16.

In Figure 31 is shown a sectional View of a beam having a V crosssection which might be formed from the structure shown in Figure 10.Such a beam will prove quite eicient when the projecting ends of thecross members are locked into a concrete oor or plastered wall.Obviously, bottom member 13 may be made larger in size than the twoupper longitudinal members 11.

In Figure 32 we show a further modification of this idea in which two ormore V sections are combined. The same requirements apply here as in theother designs.

In Figure 33 is shown a beam in cross section in which four longitudinalmembers 32 are used, one in each corner and certain of the cross membersare cut at the bottom to form projections which are then bent into theform f loops or eyes, 84. The same procedure is followed in regard tothe projections of the same members at the top of the beam. The resultis a beam which is easy to handle or ship and which lends itseli` verywell to the attachment of other structural members such as paper backedplaster base or oor base. In Figure 34 is shown a modication o-f thesame idea in which more gradual bends 81 are provided in the crossmembers 86 to serve the same purpose as the loops 84 in Figure 33. InFigure 35 is shown a further modification of the same idea. When a sheetof plaster base is forced against the projection loops, 90 of Figure 35,they are pushed through the paper backing o-f the plaster base sheet andthe insertion of a nail or straight piece of wire through the loop locksthe sheet in position.

In Figure 36 is shown another design suitable for a partition stud inwhich four longitudinal members 9| are used in much the same way as inother designs already disclosed. The transverse members 92 are arrangedto furnish X bracing and are rigidly connected to the members 9| and toeach other where they cross. They may have projections 03 extendingbeyond the outside of the stud. In Figure 37 is shown an end View ofthis stud after forming to nal shape. The X bracing members may bespaced a distance apart equal to the depth of the stud and still givequite satisfactory results.

In Figure 38 we show the side elevation of a structural beam in which adiiferent system of bracing is used. The same beam is shown in endelevation in Figure 39. It will be seen that not only are longitudinalmembers 94 used at the four corners of the section, but an additionalmember is used on either side along the neutral axis.

Each diagonal bracing member 96 extends only half the depth of the beam.While this design may appear complicated, it has certain very deniteadvantages from a manufacturing standpoint.

In Figures 40 and 41 are shown two other possible sections into whichbeams may be formed. Other sections are quite possible and we naturallydo not wish to be only limited toI those Whichwe have shown. The mostpractical sectionsfor Aour useseem to be the V, U and the box section.In this case the U really includes the `channel section. ;v In our-system of construction, there is a very definite need fora floor baseor combined floor form and steel `reinforcement as well as a plaster andstucco base as in said Patent 2,103,897. In Figure 42 is shown a plan ofone design of ribbed or stiffened mesh suitable for a plaster base butreally designed for the heavier duty required in afloor base. Figure 43is an end View and Figure 44 is aside viewofv the fabric shown in Figure42. This design is well adapted to be combined with a backingsheet ofWater proofed paper or the like tofacilitate the casting of a concreteoor around the mesh reinforcement. Referring to Figure 42, the mesh isseen to consist of a series of straight spaced longitudinal. members,|02, |03 and |04 intersected 'by transverse members |05 which arecrimped to form V bends at certain points. Longitudinal members arepreferably of a Comparatively sti material such as hard drawn wire whiletransverse members should be a softer material. Longitudinal members |02lie in the general plane of the fabric. Members |04 are located in thebottom of the V crimp as will be seen in Figure 43. Between members |03and |04 are located diagonal bracing members |06, which, in common withthe other longitudinal members, are rigidly connected at theirintersections to transverse members |05. It will be seen that thisconstruction gives a fabric rein forced by trussed V ribs at lfrequentintervals and so great is its stiffness that when made out ofcomparatively small diameter wire and fastened to floor joists, it willcarry the Weight of a man walking over it without injury to the fabric.

In Figure 45 is shown a sectional elevation of a portion of an exteriorwall and floor of a building showing how the various structural elementsdescribed inthis application are combined to form a complete structureand Figure 46 is a partial sectionvon line lI-II which makes the detailsof construction more clear. The sidewall is seen to be made up of studs|01 which may be approximately 2 x 4 inches in size for ordinaryresidence construction, may be spaced 16 inches on centers and extendtwo stories in height, if desired. At the floor line is fastened ahorizontal beam |`2 which is securely tied with special wire ties |||vto the 2 x 4 inch studs |01. These ties develop more than 2000 poundstensile strength and are easily and quickly applied. The iioor beams |08which may be 2 X 8 inches in section are framed into beams |2 and studs01. Upper and lower chord members of beam |08 are carried overcorresponding members in beam l2 and are bent around vertical members instuds |01 at ||1. Vertical members in |08 are then tied to beam ||2 at||8 and the resulting connection is actually stronger than presentstandard wood construction at the -same point. When oor beams areerected, small beams |09, which 'may be 2 x 4 or 2 x 6 inches in sectionare inserted through the iioor beams |08 and are tied at ||9 to thelower ychord to serve as bridging to distribute concentrated floorloads. It should be noted that studs '|01 and oor beams |08 are providedwith projectingmembers |20 and |2| respectively on both sides tofacilitate the anchoring of other structural material to the frame. Nextthe floor base ||3 is placed on top of the floor beams and locked bybending down the pro jecting members |2| above referred to. The sameside of the structure in the same Way, to serve as a base for Portlandcement stucco. A thin layer of rich Portland cement concrete, H22 (madewith a fine aggregate) is next placed on top of the floor base IIS,leveled off and finished. On

-account of the close spacing of ribs and Well distributedreinforcement, Which We employ, this floor slab need not be more thanone inch thick4 at its thinnest points to provide all the structuralstrength required. The Walls and ceilings are next plastered in theusual way and the exterior Walls are finished With Portland cementstucco or With any other exterior nish desired.

The exterior Walls lend themselves readily to rock Wool or other typesci insulation. lt is evident that the problems of plumbing and ofelectric Wiring are greatly simpliiied. As compared to wood, the laboroi erection will be great ly reduced because the framing Will weighabout one fth as much as its equivalent in Wood. Welding may be employedin erection but is not necessary and We believe that our present methodof tying is better as it permits a small amount of movement to permittemperature adjustment.

Obviously a fabric similar tc that shown in Fig. l0 could have beenproduced by Welding members at right angles to members 53 and 54 andthen deiorming the comple-ted fabric in the plane of the members to`produce an arrange ment similar to Fig. l0. This pattern or anymultiple of it could be easily produced in this manner and While thediagonal members would not be quite as straight as they are shown inFig. 10 they Would nevertheless function quite satisfactorily in thenished structural member.

This method of producing a trussed unit has' cerw tain practicaladvantages from a manufacturing standpoint, and by it multiples oi thesections shown in Figs. l2, 13, 31, and 32 could be easily produced.-The structure shown in Figs. 36 and 3'? could also be partially producedby this means. Other possible applications of the same idea are obvious.

If two series of spaced members such as b5 and 53 and 54 in Fig. lil'are Welded together at right angles, andthen the Welded frame isdistorted to produce an arrangement similar to Fig. 10 and then anotherseries of vmembers 55 are Welded into the structure at right angles to53 and 54 at certain pointsI it yWill be possible to produce anarrangement of members which will closely resemble a Pratt truss andwhich Will function in the same manner under exterior loads which may beapplied to it. Such a fabric could also be formed into a structuralmember as previously described. f l

Having thus described our invention, What we claim is: Y

The method of forming structural units Which consists in Welding oneseries of spaced, parallel members and a second series of members of asinuous outline disposed between certain members of the said rst seriesto a third series of spaced members which intersect the first and secondseries, cutting the members of the third series at certain points, onlines parallel to the `first-named series, to produce elongated unitsWhose axes are parallel to the first-named series, and bending thethird-named series of each unit along lines spacedlaterally of thefirst-named lines, to form a structural shape. Y

ALFRED J. EDGE. WALTER S. EDGE.

